[TowerTalk] remote switching for balanced lines - homebrew plan

[Gary Slagel]

Thanks everybody for the input.  I feel myself getting
ready for another one of my ill fated homebrew
projects :) !!  This SEEMS pretty straight forward but
my homebrewing skill are pretty suspect so I'm going
to ask for more help.  

I put a crude pencil drawing of what I'm trying to do
with the relays here: 
http://marina.fortunecity.com/sanpedro/351/family/family2/photos/photo1.html

I'm trying to implement a Cebik antenna idea he called
a 'Y-doublet' (http://www.cebik.com/edz/wy.html). 
Basically 3 88' wires arranged in a Y spaced 120
degrees from each other. By using 2 spdt relays I can
select 2 of the 3 wires to make a 176' doublet which
I'll feed with balanced line and tune from 10meters to
160meters. By selecting different combinations I can
point 3 different directions.  I'll put the relays in
a box at the top of the tower and have one balanced
line from there to the shack.  I'll need 2 separate dc
voltage control lines so I can control the relays
independently of each other.  I'll only run 100watts
at first but want to run 1000W CW in the future.  A
couple questions:

>From the feedback on this list I've got 3 different
options for the relays and wondered which would be the
most dependable:  1) Vacuum relays like the Jennings
type RF1E-26N1137 on this page (
http://www.mgs4u.com/RF-Microwave/vacuum-relays-SPDT.htm
) 2) RF Open Frame relays like the Deltrol (KO)
RNF100-SP on this page (
http://www.surplussales.com/Relays/rfopen.html ) 3)
Medium Amp Power Relays like the 7384k52 on this page
( search for part# 7384k52 at http://www.mcmaster.com/
) 

It was mentioned I'll need an rf choke on the dc
control lines.  Will that just be a ferrite core with
the line wrapped around it a few times... or a ferrite
core clipped on the line??

Does this whole scheme look reasonable or am I doomed
for another homebrew failure?

Thanks to anyone taking the time to work through this
thing with me!!

Gary






Gary Slagel/N0SXX
Lakewood, CO
http://marina.fortunecity.com/sanpedro/351

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